If you've ever worked with resin, it sticks to almost everything from wood to glass and paper to fabrics. It's a tricky material but a crowd favorite for artists and crafters. But if you're new to the resin scene, you may ask yourself, "What does resin not stick to?" The truth is that resin sticks to more things than it doesn't.
But you want to protect your countertops, create unique mixed-media art projects, and prevent adhesion issues down the road. In that case, you should know what resin does and does not stick to. But first, let's get into why resin behaves the way it does.
Why Does Resin Stick to Everything?
Resin tends to stick to many surfaces because of the chemical bonds it forms. Epoxy resins contain reactive epoxide groups that form strong covalent bonds with many substrates, reacting with hydroxyl, amine, and carboxyl groups on many surfaces. The result is a near-permanent chemical bond (it's tough to separate the resin from the surface after it's bonded).
This is complicated even further by the relatively low viscosity of most resins. As they spread out across the other surface, they form bonds across a larger surface area. Imagine cleaning up a paint spill just a few inches in diameter. Then, try to imagine cleaning up a paint spill that's a few feet in diameter. The latter would be substantially more difficult to clean before the paint sticks.
Unless you're applying resin to a completely flat surface, which is rare, the resin will flow into tiny pores and crevices as it cures and hardens. This creates a layered, interlocking adhesion, making removing all but impossible on materials like wood, fabrics, and acrylic. Fortunately, it enables us to make such strong resin phone cases.
The hydrogen bonds are the problematic agent for other materials like metal and glass, which are less porous than wood and fabric. These bonds increase resin adhesion to metal and glass, making separating difficult even though they're smooth surfaces. The most you can accomplish is breaking the resin, though the surface underneath may be permanently damaged.
While resins are a general class of materials, each type of resin behaves slightly differently:
- Epoxy resins – adhere to a wide range of materials due to their reactive epoxide groups.
- Polyester resins – tend to shrink more during curing, which can reduce adhesion strength compared to epoxies.
- UV-curing resins – cure very quickly, which can limit their ability to wet and bond to some surfaces effectively.
- Silicone resins – poor adhesion to most surfaces except silicone itself, making them useful for mold-making.
What Surfaces Does Resin Not Stick To?
Silicone
Because of its low surface energy and non-reactive nature, silicone doesn't stick to resin. This includes baking sheets, silicone plates and bowls, and silicone cups.
Silicone's molecular structure consists of alternating silicon and oxygen atoms with organic groups attached, creating a smooth, non-porous surface. This structure repels most substances, including resin. Silicone also lacks reactive sites for chemical bonding with resin, and it typically contains mold-release agents that further prevent adhesion. The combination of low surface energy, chemical inertness, and smooth texture makes silicone ideal for molds and release agents in resin casting.
Polyethylene plastics (e.g., plastic sheets, sandwich bags)
Resin doesn't stick to polyethylene plastics because of their low surface energy and non-polar molecular structure. Like silicone, polyethylene's smooth, non-porous surface lacks reactive sites for chemical bonding with resin. Its molecular chains are tightly packed, creating a barrier that prevents resin from penetrating or adhering. These plastics and petroleum, a naturally hydrophobic substance, also contain additives that further inhibit adhesion. These properties combined make polyethylene resistant to wetting and bonding, causing the resin to bead up or slide off rather than forming a solid adhesive connection.
Wax paper
Wax paper resists resin adhesion due to its paraffin or soybean wax coating. This waxy layer creates a non-polar, hydrophobic surface with low surface energy. The wax molecules form a smooth, impenetrable barrier that prevents resin from penetrating or chemically bonding with the paper substrate. The wax's melting point is typically lower than resin curing temperatures, causing it to remain slick and non-adhesive. The combination of low surface energy, chemical inertness, and physical barrier properties effectively repels resin, making wax paper an ideal release surface for resin casting and crafting but not for adhesion.
Parchment paper
Parchment paper has a silicone coating, which behaves similarly to silicone trays, plates, etc. This thin silicone layer creates a non-stick surface with shallow surface energy. This prevents resin from wetting the surface or forming chemical bonds with the wax paper. The silicone coating also fills any microscopic pores in the paper, eliminating mechanical interlocking opportunities. Its thermal stability also ensures the non-stick properties remain effective even at resin curing temperatures.
Freezer paper
Freezer paper has a polyethylene (plastic) coating on one side, which creates a non-porous, low surface energy barrier that prevents resin from penetrating or bonding. Polyethylene's non-polar molecular structure lacks reactive sites for chemical interaction with resin, and its smooth surface minimizes mechanical interlocking opportunities. These types of plastic also tend to feature a coating that contains slip agents that further reduce adhesion. The paper side may absorb resin, but the plastic-coated side remains non-stick, which makes it a good fit for protecting surfaces or creating resin molds but not sticking to the resin itself.
Teflon (PTFE)
Polytetrafluoroethylene (PTFE) is a chemical compound with dozens of industrial applications, but it is most widely known for its use in non-stick cookware. As the use case implies, it's non-stick, which includes resin. PTFE has a shallow surface energy and non-reactive molecular structure, plus the carbon-fluorine bonds create a smooth, non-porous surface that makes chemical bonding impossible.
PTFE's high density and tightly packed molecular chains form a barrier preventing resin penetration. Its hydrophobic nature repels water-based substances, including many resins. These properties combined make PTFE resistant to wetting and bonding, causing the resin to bead up or slide off rather than form a strong connection.
PVA (polyvinyl alcohol)
Resin doesn't stick to polyvinyl alcohol (PVA) because it forms a water-soluble film that acts as a release agent. Its hydroxyl groups create a hydrophilic surface, repelling hydrophobic resins. PVA's molecular structure allows it to form a smooth, non-porous barrier that prevents mechanical interlocking with resin. It also has a low surface energy that inhibits wetting and bonding with resin. When exposed to moisture, PVA dissolves, ultimately preventing adhesion. These characteristics make PVA an effective mold release agent for resin casting but not for adhesion.
Certain types of tape (e.g., painter's tape, packing tape)
Certain tapes don't adhere to resin due to their surface coatings. Painter's tape uses a low-tack adhesive and silicone release coating. In contrast, packing tape often has a polypropylene backing with acrylic adhesive. These create low surface energy barriers that prevent resin from wetting or bonding. Some tapes also contain mold release agents that further inhibit adhesion, allowing easy removal after resin curing, just as if you'd remove Scotch tape after painting.
Wax (candle wax, furniture wax)
Wax doesn't stick to resin because of its non-polar, hydrophobic nature. Its low surface energy prevents resin from wetting or bonding. Wax molecules form a smooth, impermeable layer lacking reactive sites for chemical adhesion. At resin curing temperatures, wax often melts, maintaining a slick barrier. Its inert properties and ability to fill surface pores eliminate mechanical interlocking opportunities, ensuring resin doesn't adhere.
Greasy and oily surfaces
Because of their hydrophobic, non-polar nature, grease and oily surfaces don't stick to resin. They create a low surface energy barrier, preventing resin from wetting or bonding. The oily film fills surface pores, eliminating mechanical interlocking opportunities even on surfaces like wood. Oils and greases lack reactive sites for chemical adhesion with resin. Their ability to spread and maintain a thin, uniform layer ensures consistent non-stick properties across the surface.
Some types of rubber
Resin doesn't stick to some types of rubber (both natural and synthetic types) due to their low surface energy and nonpolar nature. Rubber is smooth and non-porous, so chemical bonding and mechanical interlocking are off the table. The elastic properties of rubber also create a flexible, unstable surface that resists forming strong mechanical bonds with rigid resins. Some rubbers may even repel or degrade specific resin components.
Polypropylene plastics
Resin doesn't stick to polypropylene due to its low surface energy and nonpolar molecular structure. Polypropylene is smooth and non-porous, but it is not the ideal surface for chemical bonding or interlocking with resin. Its tightly packed molecular chains form a barrier preventing resin penetration. Its hydrophobic nature repels water-based substances, including many resins.
Nylon
Resin doesn't stick well to nylon because nylon has low surface energy and chemical inertness. Its smooth, non-porous surface lacks reactive sites for chemical bonding with resin. Nylon's hydrophobic nature repels water-based substances, including most resins. Nylon also absorbs moisture, which can interfere with adhesion. Additionally, nylon's flexibility and thermal expansion properties can cause it to separate from rigid resins during curing or temperature changes.
Mylar
Mylar doesn't adhere to resin because of its low surface energy and chemically inert structure, similar to polyester. Its smooth, non-porous surface lacks reactive sites for bonding and mechanical interlocking. Mylar often has a silicone or fluoropolymer coating, further reducing adhesion. Its high tensile strength and dimensional stability prevent mechanical interlocking. Mylar's hydrophobic nature repels water-based resins, causing them to bead up or slide off.
How to Remove Unwanted Resin
Once the resin has hardened on a surface, removing it can be challenging but not impossible. Start by scraping off as much resin as possible with a plastic tool to avoid scratching the surface. From our experience, applying heat can effectively loosen resin. Use a heat gun to warm the resin until it softens. Just ensure the temperature doesn't get too hot to avoid damaging underlying surfaces.
Check out our guide on how to get resin off your hands.
Frequently Asked Questions
Why are non-stick surfaces necessary for resin work?
Non-stick surfaces make the demolding process more manageable to create beautiful resin art.
How do I test a surface for resin compatibility?
To test a surface's compatibility with resin, apply a small amount of resin to an inconspicuous area. After curing, evaluate the bonding strength. The better the bond, the more compatible the material is with resin.
How do I remove hardened resin?
Hardened resin can be removed using heat or solvents. In some cases, peel-off methods may be used. Always take necessary precautions to protect your hands and eyes while using these methods.